Fisher–Yates

shaffle.js

shaffle = function(arr){

	var n = arr.length;
	for(var i = n - 1; i > 0; i--) {
	    var j = Math.floor(Math.random() * (i + 1));
	    var tmp = arr[i];
	    arr[i] = arr[j];
	    arr[j] = tmp;
	}

	return arr;

};